Thermal cycling stability of thermochemical energy storage system Ca(OH)2/CaO

Thermochemical energy storage (TCS) stores and releases heat through a reversible chemical reaction. And since thermochemical material (TCM) is the most important part of an energy storage system, its properties directly affect the entire system. On account of a variety of advantages such as low cost, broad availability and suitable temperature range, thermochemical method based on reversible decomposition reaction has become a famous research. In this study, a TCS experimental setup was built to investigate thermal cycling stability of the Ca(OH)2/CaO system. Through successive 20 dehydration-hydration cycles, amount of stored thermal capacity and cyclic reversibility of the Ca(OH)2/CaO system are analyzed. After research and analysis, existing problems of the Ca(OH)2/CaO energy storage system including agglomeration and sintering, poor thermal conductivity, unevenness of heat release rate are concluded and raised. After an explanation of superior performance and existing problems occurred during the dehydration and hydration process, this research lays the foundation of applying the Ca(OH)2/CaO system to practical.